Plane crash prompts partial U.N. lockdown

UNITED NATIONS (CNN) --Security was stepped up Monday at the United Nations building after the crash of a plane taking off from John F. Kennedy International Airport.

International dignitaries were on hand for high-level General Assembly debate.

U.N. Secretary-General Kofi Annan urged staff members to remain calm and expressed his shock and sorrow at the loss of life.

In a statement read by his spokesman, Annan said staff should "go about their work normally as we await further information from the U.S. authorities."

The United Nations went into a partial lockdown after the crash, banning entry by vehicles and pedestrians. The lockdown was loosened later as pedestrians were again allowed to enter the building.

The Security Council observed a moment of silence for the crash victims, issuing a statement that offered "heartfelt sympathies to the people of the United States and families of those who lost their lives."

Annan also expressed condolences for the families of those on the flight.

A loudspeaker announcement throughout the building advised people of the plane crash but declared the U.N. compound would not be evacuated. The U.N. chief of security advised the staff that closing of doors to pedestrians and cars was a precautionary move.

The U.N. practiced evacuation drills after the September 11 terrorist attacks. Last week, the U.N. was threatened by Osama bin Laden in a videotaped message. He accused the U.N. and Annan of being criminals in the bombing of Afghanistan.

A U.N. spokesman said Annan could see smoke from the plane crash from his office on the top floor of the U.N. headquarters.

Monday is day three of the U.N. General Assembly, which has brought heads of state and many foreign ministers to the U.N. headquarters. Previously scheduled U.N. meetings -- including a major political meeting of foreign ministers on Afghanistan as well as a ministerial level meeting on terrorism -- are continuing.